<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <script src="https://unpkg.com/vue@next"></script>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>练习</title>
</head>

<body>
    <div id="app">
        <h2 v-for="lesson in lessons">{{lesson.title}}</h2>
    </div>
    <script>
        lessons = [{
            title: '第一章'
        }, {
            title: '第二章'
        }]
    </script>
    <script src="index.js"></script>
</body>

</html>